FERRARI, CLAUDIOCLAUDIOFERRARIBERETTA, SARASARABERETTASALMASO, BiancaBiancaSALMASOPARESCHI, GiovanniGiovanniPARESCHITAGLIAFERRI, GianpieroGianpieroTAGLIAFERRIBASSO, StefanoStefanoBASSOSPIGA, DanieleDanieleSPIGAPelliciari, CarloCarloPelliciariGIRO, EnricoEnricoGIRO2020-12-102020-12-1020190021-8898http://hdl.handle.net/20.500.12386/28777The authors are grateful to Dr Ivo Ferreira and Dr Marcos Bavdaz for reporting the BEaTriX project results to ESA and scientific support.A new type of X-ray facility, the Beam Expander Testing X-ray facility (BEaTriX), has been designed and is now under construction at INAF– Osservatorio Astronomico di Brera (Merate, Italy) to perform the acceptance tests of the silicon pore optics modules of the ATHENA X-ray telescope. Crystals of high perfection and large dimensions are needed in order to obtain a wide beam (20 􏰀 6 cm) with an X-ray divergence of <0.500 and an X-ray energy purity 􏰅E/E < 10􏰁5. To generate X-ray diffracted beams at an X-ray energy of 1.49keV, ammonium dihydrogen phosphate (ADP) crystals have been considered among other possible choices, because of their reported crystal quality and because they can be grown at sufficiently large size at a reasonable price. In the present paper, the results of the characterization of crystalline quality and lattice planarity of a 20 􏰀 20 􏰀 2 mm ADP sample are reported.STAMPAenArticle10.1107/S16005767190046312-s2.0-85066236087000470824800012http://scripts.iucr.org/cgi-bin/paper?S1600576719004631FIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation::PE9_17 Instrumentation – telescopes, detectors and techniques